title: Immunologic consequences of antibiotic-induced abridgement of bacterial infection: effect on generation and loss of protective T cells and level of immunologic memory.
abstract: Ampicillin was employed in mice to determine the effect of rapidly abridging bacterial infection on the generation of T cell-mediated antibacterial immunity. It was found that antibiotic-induced abridgement of infection with Listeria monocytogenes had a pronounced effect on the generation of splenic T cells capable of adoptively immunizing normal recipients against a Listeria challenge infection. Ampicillin given at the time of maximum bacterial growth at 24 hr caused a striking reduction in the number of protective T cells produced at the time of peak response on day 6. Although the greatest effect was caused by giving ampicillin early in infection, a significant reduction in peak T cell production occurred even when Ampicillin was given as late as day 5. On the other hand, the effect of abridging infection at the onset of decay of the anti-Listeria response was to cause protective T cells to be lost from the spleen at a much faster rate. These results clearly show that regardless of any immunoregulatory mechanism involved, the duration of generation, and the onset and duration of decay of the anti-Listeria response are determined by the number of replicating Listeria in the tissues. Moreover, Ampicillin-induced abridgement of infection, either before or at the time of peak primary response, resulted in the expression of greatly reduced levels of immunologic memory at a later time. This indicates that memory cells are generated throughout the entire course of the primary anti-Listeria response, including the period of its decay.
mesh_terms: D000667:Ampicillin / Q000494:pharmacology*; D000818:Animals; D001424:Bacterial Infections / Q000276:immunology*; D005260:Female; D007156:Immunologic Memory / Q000187:drug effects*; D008089:Listeria monocytogenes / Q000276:immunology; D008088:Listeriosis / Q000276:immunology; D008297:Male; D051379:Mice; D008805:Mice, Inbred A; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D013601:T-Lymphocytes / Q000187:drug effects*
chemical_list: D000667:Ampicillin